Diaminobenzoic-acid alkamin ester.



UNITED STATES PATENT OFFICE.

ALFRED EINHORN, OF MUN IGli, GERMANY, ASSIGNOR TO FARBWERKE VORM. MEISTER LUCIUS & BRUNING, OF HUCHST-ON-THE-MAIN, GERMANY, A OORPORATION OF GER- MANY.

To all whom it may concern:

following is av specification.

alkaline with I have found new alkaniin esters which are derived from meta-para-diaminobenzoic acid or its alkyl-derivatives corresponding to the following formula COOH wherein R means alkyl or hydrogen. The alkamin esters of these acids are valuable as medicaments being-characterized by a powerful anesthetic" action. These compounds are little soluble in water, but readily soluble in alcohol, ether, and benzene, forming hydrochloride readily soluble in water with neutral action and from which alkalies separate the alkamin esters. These esters are hydrolized on boiling with free alkali and .m'eta-para-diaminobenzoic acid or its alkyl derivatives are formed. The new alkamin esters of said acids may be obtained, for instance, by heating the acids with an alka'min in concentrated sulfuric acid.

The process may be carried out, for instance, as follows :-15 parts by weight of meta-para-diaminobenzoic acid and 30 parts by weight of diethylaminoethanol are introduced while well cooling into 150 parts of concentrated sulfuric acid. The mixture isheated on the water-bath for from 5-6 hours and the solution is then poured on ice, made ammonia and saturated with potash and shaken with ether. The ethereal solution thus obtained is washed with water to remove any diethylaminoethanol and the other is evaporated. The diaminobenzoic acid diethylaminoethanol ester is then obtained as an oil readily soluble in alcohol, benzene and ether. With the equivalent quantity of hydrochloric acid it forms a monohydrochlorid readily soluble in water with a neutral reaction and crystallizing from alcohol in form of needles whichanelt at 163 C.

The alkamin ester has the formula:

nnneoanoooc um c 11,

Specification of Letters Patent. Application filedvseptember 19, 1907. Serial No. 393,583.

Be it known that I, ALFRED EINHORN, a

DIAMINOBENZOIC-ACID ALKAMIN ESTER.

Patented Dec. 15, 1908. (Specimens.)

and is formed according'to the equation:

On boiling the ester with caustic soda-lye, the sodium salt of meta-para-diaminobenzoic acid is obtained, besides alkamin.

The product claimed is used for local anesthesia and is administered in g-} 1- and 2 per cent. solutions, the 9, and per cent. solutions being employed in quantities up to 100 0.0. for infiltration anesthesia, and the 1 and .2 per cent. solutionsin quantities of from 1-10 c.c. for central conductive anesthesia.

Having now described my invention, what I claim is 1. As products, the alkamin esters of meta-para-diaminobenzoic acid and alkyl derivatives thereof, having the constitution 0,11, (NR, 2000K wherein R means alkyl and hydrogen and X the radical of an alkamin, being compounds little soluble in water, but readily soluble in alcohol, benzene and ether, forming in water readily soluble hydrochlorids of neutral reaction from which alkalies liberate the alkamin esters which on boiling with free alkalies are hydrolized with formation ters having a local anesthetic action.

2. As a new inobenzoic acid diethylamino-ethanol ester having the formula:

0 H,(NH,)2COOC,H,N(C,H,), being an oil little soluble in water, readily soluble in alcohol, ether and benzene, yielding when boiled with caustic soda-lye the of the corresponding acids; the alkamin esproduct, the meta-para-diamsodium salt of meta-para-di.aminobenzoic acid, forming a monochlorhydrate which melts at 163 C. and-which separates the alkamin ester on addition of potash, the aqueous solution of the monochlorhydrate being of neutral reaction and acting as a local aneslhetic. I i

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

ALFRED EIN HORN.

Vfitnesses:

ABRAHAM SCHLESINGER, Louis F. MUELLER;

lOO 

